Sounds like the USA. The oil and gas industry has an extra twist in #3 which would read: 3. Producing field get exhausted or becomes uneconomic to operate, com

Sounds like the USA. The oil and gas industry has an extra twist in #3 which would read: 3. Producing field get exhausted or becomes uneconomic to operate, company sells field to smaller less-capitalized operator who reworks some wells in an effort to pay back their investment. 4. Smaller operator eventually sells to a mom-and-pop operator who operates a series of stripper wells in the field. Once production from these wells decline to the point where this under-capitalized operator can no longer profit the field is abandoned and tax payers are left to fund the cleanup. All of this can take decades before abandonment and any technological advance during that time could make the field more attractive to large operators who would then buy these fields from the mom-and-pops and mid-size operators so they could squeeze even more profits before cycling back into the later steps of the loop. Over a long enough time period you have a Texas which is dotted with tens of thousands of orphaned or abandoned wells. Many of these wells leak oil, natural gas, or brines into shallow surface aquifers when the old production strings inevitably rust away. The problem is worse when new tech maintains production in an area since wells that were abandoned years or decades ago but never plugged are effectively open to atmospheric pressure and when a technique like hydraulic fracturing is used downhole, it repressurizes formations and can force fluids up thru unplugged wellbores to the surface where, if controls are not in place, fluid spills are inevitable. When that happens in an area that had been abandoned the operator responsible for the increased pressure would argue that cleanup is not their responsibility since the previous owner was responsible (had paid a bond to the state) for the plugging and abandonment of the leaking well. It's more complicated than this but you get the idea. It's never their problem and the wrong people tend to get stuck with remediation expenses.